Primarily in the health care industry, but also in many other commercial and industrial applications, it is often necessary to monitor the effectiveness of the processes used to sterilize equipment such as medical and non-medical devices, instruments and other articles and materials. It is often standard practice in these sterilization processes to include a sterilization indicator in the batch of articles to be sterilized. This allows a direct approach to assay the lethality of the sterilization process.
Conventional sterilization indicators typically contain a biological indicator. The biological indicator may comprise one or more test organisms which are designed to be more resistant to the sterilization process than the organisms to be destroyed by the sterilization. These test organisms are usually bacterial spores. Conventional sterilization indicators may be available in two forms.
The first of these forms involves the use of a substrate wherein bacterial spores are directly applied or inoculated on the substrate. The substrate may be fully covered with the spores. Any physical handling by the user may result in spores being lost from the substrate, transferred to the user, or potentially contaminating or being contaminated by the surrounding area. It has been proposed to provide special clips to allow the user to handle the substrate. However, these clips often hinder the sterilization process and may result in a faulty test result. Also, minimum size constraints for these substrates typically lead to the requirement for relatively large volumes of incubation medium, for example, from about 5 to about 10 milliliters (ml), and relatively long incubation periods, for example, from about 2 to about 7 days.
The second of these forms involves a self-contained sterilization indicator. These sterilization indicators typically contain the bacterial spores and the incubation medium in a single container, but in separate compartments. The spores are subjected to the sterilization process. Following sterilization, the container is activated so that any surviving spores may come into contact with the incubation medium to determine the effectiveness of the sterilization. These sterilization indicators may be useful in gaseous sterilization processes, but are typically not suitable for liquid sterilization processes.
A major drawback with each of these sterilization indicators relates to the time delay in obtaining results for the sterilization test. These sterilization indicators normally require that the bacterial spores be cultured for at least two and often up to about seven days to assure adequate detection of any surviving spores. During this time, the articles that went through the sterilization process and are under evaluation should not be used until the results of the spore viability test have been determined. However, many health care facilities have limited resources and must reuse their “sterilized” instruments within 24-48 hours and often immediately. In such settings, the two to seven day holding period for sterility verification may be impractical, costly and inefficient.
Thus, a problem that has been presented by the art is to provide a sterilization indicator that minimizes or eliminates the handling of the biological indicator and accurately detects the effectiveness of a sterilization process within a relatively short period of time. It would be advantageous if this sterilization indicator could be adaptable to liquid sterilization processes as well as gaseous sterilization processes. The disclosed technology, in at least one embodiment, may provide a solution to this problem.